Mass-loss from massive globular clusters in tidal fields. Issue 2 (8th March 2021)

• Record Type: Journal Article
• Authors: Meiron, Yohai; Webb, Jeremy J; Hong, Jongsuk; Berczik, Peter; Spurzem, Rainer; Carlberg, Raymond G
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 503:Issue 2(2021)
• Page Start: 3000
• Page End: 3009
• Publication Date: 2021-03-08
• Subjects: methods: numerical -- stars: kinematics and dynamics -- globular clusters: general; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stab649
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Massive globular clusters lose stars via internal and external processes. Internal processes include mainly two-body relaxation, while external processes include interactions with the Galactic tidal field. We perform a suite of N -body simulations of such massive clusters using three different direct-summation N -body codes, exploring different Galactic orbits and particle numbers. By inspecting the rate at which a star's energy changes as it becomes energetically unbound from the cluster, we can neatly identify two populations we call kicks and sweeps that escape through two-body encounters internal to the cluster and the external tidal field, respectively. We find that for a typical halo globular cluster on a moderately eccentric orbit, sweeps are far more common than kicks but the total mass-loss rate is so low that these clusters can survive for tens of Hubble times. The different N -body codes give largely consistent results, but we find that numerical artefacts may arise in relation to the time-step parameter of the Hermite integration scheme, namely that the value required for convergent results is sensitive to the number of particles.